The present invention relates to a picture recording method and an information processor performing the method. More particularly, the invention relates to a method for encoding picture data to be output onto a television monitor, as well as to an information processor that encodes the picture data according to the method. The invention further relates to a presentation system that performs picture encoding and display.
In recent years, when great quantities of picture data representing still and moving pictures are to be stored or transmitted, it has been customary to encode the picture data to reduce its size.
Today, one of the most widely recognized international standards for encoding still picture data is the algorithm recommended by the JPEG (Joint Photographic Experts Group) composed of experts from two organizations: the ISO (International Organization for Standardization) and the CCITT (International Telegraph and Telephone Consultative Committee; later reorganized into the ITU-T, which is the International Telecommunication Unionxe2x80x94Telecommunication Standards Sector).
On the other, the algorithm recommended by the MPEG (Moving Picture Experts Group), a subordinate group of the ISO, is widely recognized as the preferred international standard for encoding moving picture data.
In the description that follows, picture data encoded by the JPEG algorithm will be referred to as JPEG data and data encoded by the MPEG algorithm as MPEG data. The techniques involved are detailed illustratively in xe2x80x9cA Point-by-Point Illustrated Approach to the Latest MPEG Techniques,xe2x80x9d a Japanese publication from ASCII Publishing Co. in Japan.
Suppose that a picture with a resolution of 704xc3x97480 pixels is encoded conventionally, i.e., by the JPEG algorithm and that the encoded data is later decoded for display on a television monitor. In such a case, as described in xe2x80x9cDigital Video Technology: A Simple Approachxe2x80x9d (a Japanese publication from NHK Publishing Co.), not all of the data representing the resolution of 704xc3x97480 pixels are displayed on the television monitor because of fuzziness caused by interlaced scanning of the television set.
It is therefore an object of the present invention to provide a picture recording method for recording original picture data in such a manner that when the data is recorded, the original picture in its entirety will be displayed at its original resolution on a television monitor; and more specifically to provide a picture encoding method for encoding original picture data in such a manner that when the encoded data is decoded, the original picture in its entirety will be displayed at its original resolution on a television monitor.
It is another object of the invention to provide an information processor for encoding original picture data in such a manner that when the encoded data are decoded, the original picture in its entirety will be displayed at its original resolution on a television monitor.
It is a further object of the invention to provide a picture processing system for encoding original picture data in such a manner that when the encoded data are decoded, the original picture in its entirety will be displayed at its original resolution on a television monitor, the picture processing system further transmitting the encoded original picture data to a separate information processor of a highly portable type, such as a digital still camera, which in turn decodes the received data to display the original picture in its entirety at its original resolution on a television monitor connected to the information processor.
In achieving the foregoing and other objects of the present invention and according to one aspect thereof, there is provided a picture encoding method that begins with scaling down an original picture image and filling the top, bottom, and left and right side regions around the scaled down picture image with pixels having suitable color information for attaining an original resolution of the original picture image so that the original picture image is encoded at the original resolution. Then, the encoded picture data is decoded for displaying all pixels of the original picture image at the original resolution on a television monitor.
Preferably, according to the invention, the picture encoding method includes scaling down the original picture image while meeting the conditions of
X=SXxe2x88x92(a1+a2)
Y=SYxe2x88x92(b1+b2)
where, as shown in FIG. 4, X stands for a width of the scaled down picture image, Y for a height of the scaled down picture image, SX for a width of the original picture image yet to be scaled down, SY for a height of the original picture image, a1 for a width of a group of pixels filling the region on the left side of the scaled down picture image, a2 for a width of a group of pixels filling the region on the right side of the scaled down picture image, b1 for a height of a group of pixels filling the region on top of the scaled down picture image, b2 for a height of a group of pixels filling the region at the bottom of the scaled down picture image; wherein al, a2, b1 and b2 are any integers which are larger than 0 and which further satisfy the conditions of a1 less than SX, a2 less than SX, b1 less than SY, and b2 less than SY.